To add to what jean-paul said (again with my personal perspective): I'll take a soldering iron to the $50 DAC without giving it much thought. But for me, the Soekris boards are too expensive to modify directly (except for the most trivial/simple stuff with virtually zero chance of ruining it).
Also, some considerations for the NOS DAC cons:
Also, some considerations for the NOS DAC cons:
- JP addressed the power supply issue; also, that transformer he linked is what I already had on hand, which was originally purchased for my Soekris DAC
- Balanced output: the Soekris supports it out of the box via opamps; you could implement the same fairly easily for the cheap board (or likely buy the equivalent). Going balanced dual mono with Soekris doubles the cost. Also, read Alexandre's comments above on balanced vs single-ended: I'm personally re-considering the need for balanced interconnects.
- Headphone out: I haven't tried, but the cheap board might be able to drive some headphones. Again, Soekris-equivalent (op-amp headphone driver) isn't terribly complex or expensive.
- No direct I2S: true, but IMO it's trivial to solder wires to the IC pins
- No filters: lack of digital filters is a feature of NOS DACs
- No firmware updates: no FPGA or digital logic chips means no need for firmware
Both 1387 DACs I have tried will play 24/192 files without issue. My understanding is that you get truncation of the lowest 8 bits this way, which of course SEEMS like it would sound bad vs. dithering to 16/192, or playing on a fully HD capable DAC. Bizarrely enough, I actually still prefer the 1387's tonality (with truncation!) in some ways to some other true 24-bit DACs I have heard. And I haven't yet found a dither algorithm that sounds better than just leaving the data alone, although I want to try more.
Thank you so much for all your answers.
It's really unfair, I know. They're in different leagues. The learning part is calling me though.
That's a good point
Got it.
Good to know, thank you. I'm trying to improve from a very clean but fatiguing PCM5122 DAC, and the Soekris is a great board, but the 1387 looks like the nostalgic good choice.
I think I'll go the impulsive(-ish) path and get one as well for a change, I tend to overthink all my life decisions
It's really unfair, I know. They're in different leagues. The learning part is calling me though.
That's a good point
Also, some considerations for the NOS DAC cons:
- JP addressed the power supply issue; also, that transformer he linked is what I already had on hand, which was originally purchased for my Soekris DAC
I would need a more complex trafo if I want a secondary to power the RPi as well (w/ a regulator in between). Also, I have an old broken Rotel amp I could probably get the trafo from, but I don't know exactly the secondaries it has.
I have a pair of Modulus86 in the closet, and I think Tom recommends a real balanced input if possible, but also explains how to build a fake balanced cable. So I could go that route as well.
Noted, will do a search on op-amp headphone boards.
That one looks quite straightforward even for an untrained eye. I can always buy a SPDIF to I2S board anytime.
[*] No filters: lack of digital filters is a feature of NOS DACs
[*] No firmware updates: no FPGA or digital logic chips means no need for firmware
Got it.
Good to know, thank you. I'm trying to improve from a very clean but fatiguing PCM5122 DAC, and the Soekris is a great board, but the 1387 looks like the nostalgic good choice.
I think I'll go the impulsive(-ish) path and get one as well for a change, I tend to overthink all my life decisions
I've always done the latter, i.e. straight from RPI to DAC pins. Just try to keep the wires as short as possible (10cm or less is the general recommendation). Easiest is if you get a bulk pack of jumper wires, with a female connector on one end. Grab three of them, cut the other end off and strip a bit of insulator off, and solder directly to the DAC IC pins.
That's the quick and easy way to start. However, note the RPI's native I2S is imperfect: its clock is not an integer multiple of 44.1khz, so you get I2S that is approximated in terms of timing. The fix is to use an I2S re-clocker (such as iancanada's board, or the Allo Kali), or you could use a USB to I2S as you suggested. Personally, I like to start with the simplest approach, and slowly add features and enhancements.
I was afraid of that (reclocker). Gonna try to summarise my case
SOEKRIS
+ direct isolated I2S input (and others).
+ reclocker,
+ un+buffered and balanced/SE outputs,
+ headphones amp,
- 180-260€ per board depending on resistors precision.
+ Basically, full featured plug&play DAC
TDA1387
+ NOS
- only SPDIF in (have to solder I2S pins to the DAC and most likely have to add a reclocker)
- needs a board to convert RCA into balanced
- needs a headphones amp.
+ Fun doing proper DIY
+ 50€ DAC,
- and approx 100-200 more for the other two or three boards.
+ Pseudo-modular system, once invested in all the options, you can replace the DAC board more often since it's cheaper.
Money wise it'll be approximately the same investment I guess, Soekris even a bit cheaper in the end.
So decision should probably be based on which one sounds more natural? I'm upgrading from a IQaudIO DAC+ (clear but fatiguing). I know that'll always depend on the implementation (quality of those extra boards I would need for the TDA1387) so I'm lost again.
Sorry for boring you with off topic questions, if no one noticed I'm extremely over-analizer. If you read down here thank you so much
Given the way you framed it, I'd probably give the nod to the Soekris. I'm deliberately ignoring the "which one sounds more natural" question because I don't feel equipped to answer that. But if you're looking for a particular sound, the Soekris offers, out of the box, more ways to tweak to your liking, through the use of digital filters.
One more option, just to add to your analysis paralysis: there is a USB-powered, 4x tda1387 DAC available at the usual places, generally around $25. Here is one example. This is by no means the best representation of the tda1387, but it might give you a sense of the chip. That is, if you get this and absolutely hate it, then tda1387 probably isn't for you. But if you think that with some refinement it might be what you're looking for, maybe that's your answer.
OK, one more option: the tda1387 chip itself is cheap, you should be able to source them for $1/each or less. A very basic implementation can be created on breadboard for very little money. Something like this:
But if you're looking for a particular sound, the Soekris offers, out of the box, more ways to tweak to your liking, through the use of digital filters.One more option, just to add to your analysis paralysis: there is a USB-powered, 4x tda1387 DAC available at the usual places, generally around $25. Here is one example. This is by no means the best representation of the tda1387, but it might give you a sense of the chip. That is, if you get this and absolutely hate it, then tda1387 probably isn't for you. But if you think that with some refinement it might be what you're looking for, maybe that's your answer.
OK, one more option: the tda1387 chip itself is cheap, you should be able to source them for $1/each or less. A very basic implementation can be created on breadboard for very little money. Something like this:
- 5v power supply (e.g. USB charger)
- 220uF (or more) 10v PSU decoupling cap
- 100nF 50v X7R (or C0G) PSU decoupling/high freq filter cap
- Capacitor for pin7/VREF (1uF per datasheet, or 1000uF or more for better bass)
- Two 2.2uF (or greater) output caps for DC-blocking (ideally film)
- Two I/V resistors (in the range 2.7k to 3.5k)
- Two 1.5nF film or ceramic caps as a basic high-frequency filter
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I'm actually re-reading the series of posts at hifiduino and dimdim blogs and TBH I think my best bet is to go the Soekris path. Even being a "plug&play" there's many DIY stuff I can do on the software side (arduino to control vol / filters / source) and even hardware (LCD et al). I'm really grateful in any case for all the information given in this thread, Matt & all, more knowledge is always welcome, I do really appreciate.
Sort of OT, but since we are sharing different 1387 boards, I have to say that the Audiophonics board sounds remarkably good. I pulled the Nichicon ES output caps and after trying the usual suspects, settled on some 0.33uF WIMA MKP4, which made a big improvement. They are in parallel with the input caps of my amp, otherwise I couldn't get away with such a small value. I am also using a new OPC regulator to feed the Pi courtesy of Greg Stewart. The detail is great (maybe 8x chips really does help?) and tonality is full and vivid...very satisfying.
Attachments
Matt, thanks for the consideration.
The main point I was trying to make is that doubling up the DACs to make a "balanced" signal (perhaps we should call it differential, or symmetric, rather than balanced) is not the way to go, in my opinion. I find that it alters the harmonic distortion in a non-musical way. It just doesn´t sound as good as a single dac, or two paralleled dacs.
A less important note, balanced actually means balanced impedance. Usually, all you need is one extra resistor to make a balanced signal from a single ended source. Then your receiver should be able to use the difference between hot and cold, and ignore ground noise. It´s all in that article by Bruno putzeys: the g word
(About harmonic distortion. Some people are paying $7000 for a box that produces some adjustable second and third harmonics. This product is a hit, apparently. Take a look: Vertigo Sound VSM-2 Mix Satellite MK2 - Full Version - Vintage King Pro Audio Outfitter
I tell you, why not use a TDA1543 and passive I/V instead? I think the outcome will be close to the above box used with typical settings. I actually like the 1543 and passive I/V, but I also like the cleaner low distortion active versions I made. It depends on what you listen, and sometimes it is just nice to make a change.)
Thanks,
Alex
I don't think it's offtopic, IMO anything tda1387-related is fair game in this thread.
I've always been curious to try that DAC. I have more tda1387 DACs than any sane person needs (though I suspect Abraxalito has me beat!) There is a very similar one from TeraDak. If you haven't already, take a look at this thread, Improving passive I/V for Pi dac 8 x TDA1387. That's about the TeraDak model. But if you take the time to back out the output schematic for your Audiophonics, there's a chance it might be similar to the TeraDak. If so, that thread demonstrates that the stock output filter may not be optimal.
Don't you mean that your DAC output caps are in series with your amp's input caps?
What is the board on your stack between the RPI and Kali?
Thank you for the clarification. I've always used those terms interchangeably, but I see that's imprecise. It's been a while since I've read "The G Word" (obviously!), it's probably time to re-visit.
When you say "the above box", to which are you referring? We've discussed lots of DACs in this thread.
It's funny you mention 1543. My very first NOS DAC was one of those cheap 4x Muse tda1543 USB-powered DACs. I didn't like it. There's a huge thread on Head-Fi that discusses numerous mods for it. At the time my skill level was lower (not to imply it's high now) so I didn't understand the nature of several of those mods, so only did the absolute simplest. I remember liking it a little bit in some cases, but something I noticed in cymbals really turned me off.
I dismissed NOS until I got the tda1387x8 DAC, and I've been obsessed ever since. I've always wanted to go back and give the 1543 another try, now that I have a little more experience. The only problem is time! Too many projects!
Matt
I meant the distortion box! The one I wrote about. Second and third harmonic generator. I actually downloaded a trial of a plugin that models said distortion box, and listened to the results with my clean DAC. I tell you, a dac with tda1543 + passive I/V has a similar sound to the $7000 distortion generator.
I have to revisit the 1387.
BTW, I get very good cymbals and top end in general by using transformer coupling. Has to do with the filter function of the trafo, certainly. I still haven´t tried a high order filter like Richard does.
-Alex
When you say "the above box", to which are you referring? We've discussed lots of DACs in this thread.
I meant the distortion box! The one I wrote about. Second and third harmonic generator. I actually downloaded a trial of a plugin that models said distortion box, and listened to the results with my clean DAC. I tell you, a dac with tda1543 + passive I/V has a similar sound to the $7000 distortion generator.
I have to revisit the 1387.
BTW, I get very good cymbals and top end in general by using transformer coupling. Has to do with the filter function of the trafo, certainly. I still haven´t tried a high order filter like Richard does.
-Alex
The thing about the 1543 is that you have to select chips. There is a lot of variability. I believe John (ECDesigns) has gotten to the bottom of this, he says the MSB is the least accurate of all bits, and only 5% of all tda1543 are really good.
With 1387 you don´t need to worry about this. It uses segmentation, aka sign magnitude, which mitigates any lack of MSB accuracy and the zero crossing problem (all bits change state at the same time during the zero crossing with TDA1543 and 1541).
-Alex
With 1387 you don´t need to worry about this. It uses segmentation, aka sign magnitude, which mitigates any lack of MSB accuracy and the zero crossing problem (all bits change state at the same time during the zero crossing with TDA1543 and 1541).
-Alex
Looks like the same exact circuit with a slightly different layout, better connectors, and a 4 extra electrolytics. So according to Abraxalito, in addition to some NOS droop correction, there is a 1dB bass boost built in with the stock filter on this board...lol maybe that is why these low value output caps are working out for me?
Well, it isn't what I meant, but I'm sure it is what I should have meant.
I have a lot to learn, obviously!That's IanCanada's IsolatorPi. To my ears, it makes the Pi a much better player.
It won't really be a mod, just soldering wires directly to pins 1, 2 and 3 of the DAC IC.
No pins for a pot. But I don't see why you couldn't hang one off the output.
Please post your thoughts and impressions when you get it! My (decidedly non-golden) ears say it's pretty decent.
Attached are some better pics.
Hi Matt,
I finally received my "little giant" and had the chance to hook it up for a short listen tonight. It seemed a little unfocused at first, but after I let it burn in for 1/2 hour or so it tightened up nicely. I agree with you, for the money it sounds great. Compared to a PCM1794 EZ dac that I have in the same system and after only a very brief listen without swapping in and out a few times, my impression is that the EZ dac has a lower noise floor, seems more dynamic, and images better. The little giant is smoother/softer around the edges, and doesn't bring as much background ambiance. I preferred my Subbu dac to the EZ dac as it had more detail and lower noise floor to my ears. I want to let is burn in and settle for a few hours before I give it a serious A/B comparison with my other dacs. Besides the EZ dac I have a dual mono Opus dac from twisted pear. But so far for the money it's a no brainer.
Paul
If you're interested in ideas for modding the 'little giant' we're talking about it over here : AliExpress AD1865 R2R DAC
A bit late to the build. Anyway finished a TDA1387 balanced DAC. I am using a Pi 3. Volumio is the software I have been using on a Pi, Kali, Piano. That combo works well together.
I am having no joy with this build. I am guessing I may have soldered the ICs incorrectly or overcooked them on the hot plate. Also, when I configure Volumio it asks for which DAC is installed. Quite a few listed, so perhaps that is also a problem.
I have attached photos in showing how the devices are mounted. The first photo closest to the 40pin has them all right reading. Second photo is from the output side.
Any thoughts appreciated.
David
I am having no joy with this build. I am guessing I may have soldered the ICs incorrectly or overcooked them on the hot plate. Also, when I configure Volumio it asks for which DAC is installed. Quite a few listed, so perhaps that is also a problem.
I have attached photos in showing how the devices are mounted. The first photo closest to the 40pin has them all right reading. Second photo is from the output side.
Any thoughts appreciated.
David
